4.x: Improve the Testcontainers user experience with Podman

[romain-grecourt]

Enhancement Description

Using Testcontainers with Podman requires some configuration and does not work out of the box.
Podman is a popular container runtime alternative to Docker, especially on RedHat based systems.

See the following links:

• https://java.testcontainers.org/supported_docker_environment/#podman
• https://podman-desktop.io/tutorial/testcontainers-with-podman
• https://stackoverflow.com/questions/71549856/testcontainers-with-podman-in-java-tests

Investigate if we can implement some heuristic to detect Podman and configure Testcontainers automatically.

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Testcontainers has an SPI org.testcontainers.dockerclient.DockerClientProviderStrategy that can be implemented to customize the configuration of the docker client.

This would be an ad-hoc test dependency added explicitly by users in their projects.

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Or, we could provide some utility that generates testcontainers.properties in the class-path.
This can be done with some Maven plugin/extension.

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When Podman is used in rootless mode, Ryuk needs to be disabled. It can only be disabled with an environment variable:

TESTCONTAINERS_RYUK_DISABLED=true

This means that disabling Ryuk programmatically is challenging, we should do this only if "rootless" mode is the default.

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We could use Maven to inject configuration to surefire and failsafe (via profile, or programmatically with a Maven extension) to define the value of the environment variable to point at a Maven property. That Maven property can be set programmatically before the test executions.

However this approach for IDEs that don't use Maven to execute the tests (E.g. IntelliJ)

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Modifying the value of an environment variable in-flight is not pretty and should be avoided, see https://github.com/junit-pioneer/junit-pioneer/blob/ef5ccff6ea9b12b82698aee24e6661de13d242df/src/main/java/org/junitpioneer/jupiter/EnvironmentVariableUtils.java#L36.

We could also pre initialize the ResourceReaper instance to bypass the environment variable:
https://github.com/testcontainers/testcontainers-java/blob/7209ff67f85fa7ef80f3e2e7f9c08db57769fe1d/core/src/main/java/org/testcontainers/utility/ResourceReaper.java#L58

This would require reflection to modify a private field.
This hack can be implemented as part of the DockerClientProviderStrategy implementation as the ResourceReaper initialization happens after.